Known run-flat devices for multi-block rims generally consist of an annular supporting structure which is mounted around the rim inside a tire cover and which is equipped with means of locking the beads of the cover against the flanges of the rim, such as annular wedges that connect the annulus to these beads.
Document EP-A-1 900 551 in the name of the Applicant Company describes such a device in which the supporting structure is split into annulus sectors, each comprising rigid supporting elements that are superposed and separated from one another two by two by an elastic layer consisting, for example, of a rubber/metal reinforcement composite in the form of an arc of a cylinder so that a relative axial movement of the sectors is permitted by the shearing of this layer under a lateral force applied to the structure.